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N18 ICD-10-CM Code: Chronic kidney disease (CKD)

Compare with another code for N18Check this code on a claim

Billing Status: NO. This is a non-billable ICD-10-CM code: report a more specific billable code beneath it.

Coding at a Glance

Official instructions
11 Excludes2 · 3 use-additional instructions · 3 code-first instructions

What these terms mean →

Category · FY2027A non-billable heading in the tabular list: report a more specific code beneath it.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too, and is marked with where it comes from.

Code firstSequence the underlying condition before this code
Use additional codeReport with this code when documented
  • Use additional code, if applicable, to identify:
  • associated cachexia (E88.A)
  • kidney transplant status (Z94.0)
Excludes2from N17-N19Not included here; may be reported together
  • congenital renal failure (P96.0)
  • drug- and heavy-metal-induced tubulo-interstitial and tubular conditions (N14.-)
  • extrarenal uremia (R39.2)
  • hemolytic-uremic syndrome (D59.3-)

+7 more in Instructions

Where it sits Source: CMS/NCHS

Under:Chapter 14: Diseases of the Genitourinary SystemN17-N19 Acute kidney failure and chronic kidney disease

Codes under N18 (7)

  • N18.1Chronic kidney disease, stage 1Billable
  • N18.2Chronic kidney disease, stage 2 (mild)Billable
  • N18.3Chronic kidney disease, stage 3 (moderate)Not billable
  • N18.4Chronic kidney disease, stage 4 (severe)Billable
  • N18.5Chronic kidney disease, stage 5Billable
  • N18.6End stage renal diseaseBillable
  • N18.9Chronic kidney disease, unspecifiedBillable

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for N18 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on N18 itself; “inherited from” names the category or block whose note applies here.

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from N17-N19

Code First

Underlying conditions that must be sequenced before this code.

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code, if applicable, to identify:
  • associated cachexia (E88.A)
  • kidney transplant status (Z94.0)

Coder workflow for N18

MedCoder structured workflow — derived from this code’s own official record

Before you code N18

  1. N18 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

    ReviewN18.1, N18.2, N18.3, N18.4, N18.5, N18.6, N18.9

    See the relationships section · Guide: How to choose an ICD-10-CM code →

Choose the right path

  1. Does the documentation support one of the more specific codes beneath N18?
    Yes → Select that code and continue the checks below on its own page.
    No → N18 cannot be reported as written. Where the codes beneath it include an unspecified code, that code applies when the record goes no further; otherwise query for the missing detail.

    ReviewN18.1, N18.2, N18.3, N18.4, N18.5, N18.6, N18.9

  2. Is the underlying (etiologic) condition the Code First note names documented?
    Yes → Sequence the underlying condition first, then the code beneath N18.
    No → Continue; do not add an underlying condition the record does not document.

    ReviewE08.22, E09.22, E10.22, E11.22, E13.22, I12

Report the code beneath N18 that the documentation supports, not N18 itself. Then work the Use Additional Code note, and confirm that code is valid for the date of service on its own page.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Acuity
Acute or chronic as documented; when both are documented and separate codes exist, both are reported with the acute code first (Guidelines I.B.8).
The underlying (etiologic) condition
Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes2 — not part of N18(11 notes)

    Coding workflow: The conditions named in this note are not included in N18. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareP96.0, N14, R39.2, D59.3, K76.7, O90.41

    See the official tabular notes · Guidelines I.A.12.b

  • Code First — sequencing check(3 notes)

    Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before N18. Do not add an underlying condition the record does not document.

    ReviewE08.22, E09.22, E10.22, E11.22, E13.22, I12

    See the official tabular notes · Guidelines I.A.13

  • Use Additional Code — after identifying N18(3 notes)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with N18 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewE88.A, Z94.0

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The underlying condition the Code First note names is documented alongside this condition.

Coding question: How are the two sequenced?

Path: Review the Code First note.

Reason: The underlying condition is sequenced first and the manifestation follows (Guidelines I.A.13).

ReviewE08.22, E09.22, E10.22, E11.22, E13.22, I12

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with the code beneath N18?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

ReviewE88.A, Z94.0

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Don’t confuse N18 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of N18 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • P96.0— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of congenital renal failure adds P96.0; it is not part of this code and both may be reported when both are documented.

    Full comparison: N18 vs P96.0 →

  • N14— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of drug- and heavy-metal-induced tubulo-interstitial and tubular conditions adds N14; it is not part of this code and both may be reported when both are documented.

    Full comparison: N18 vs N14 →

  • R39.2— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of extrarenal uremia adds R39.2; it is not part of this code and both may be reported when both are documented.

    Full comparison: N18 vs R39.2 →

  • D59.3— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of hemolytic-uremic syndrome adds D59.3; it is not part of this code and both may be reported when both are documented.

    Full comparison: N18 vs D59.3 →

  • K76.7— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of hepatorenal syndrome adds K76.7; it is not part of this code and both may be reported when both are documented.

    Full comparison: N18 vs K76.7 →

  • O90.41— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of postpartum hepatorenal syndrome adds O90.41; it is not part of this code and both may be reported when both are documented.

    Full comparison: N18 vs O90.41 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Chronic kidney disease (CKD) is a non-billable ICD-10-CM category code (N18). A more specific billable subcode must be selected for claims submission.

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 9: Diseases of the Circulatory System (I00 -I99)

2) Hypertensive Chronic Kidney Disease Assign codes from category I12, Hypertensive chronic kidney disease, when both hypertension and a condition classifiable to category N18, Chronic kidney disease (CKD), are present. CKD should not be coded as hypertensive if the provider indicates the CKD is not related to the hypertension.

Chapter 9: Diseases of the Circulatory System (I00 -I99)

The appropriate code from category N18 should be used as a secondary code with a code from category I12 to identify the stage of chronic kidney disease.

Chapter 9: Diseases of the Circulatory System (I00 -I99)

The ap propriate code from category N18, Chronic kidney disease, should be used as a secondary code with a code from category I13 to identify the stage of chronic kidney disease.

Chapter 14: Diseases of Genitourinary System (N00-N99)

2) Chronic kidney disease and kidney transplant status Patients who have undergone kidney transplant may still have some form of chronic kidney disease (CKD) because the kidney transplant may not fully restore kidney function. Therefore, the presence of CKD alone does not constitute a transplant complication. Assign the appropriate N18 code for the patient’s stage of CKD and code Z94.0, Kidney transplant status. If a transplant complication such as failure or rejection or other transplant complication is documented, see section I.C.19.g for information on coding complications of a kidney transplant. If the documentation is unclear as to whether the patient has a complication of the transplant, query the provider.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. Sequencing: 3 Code First instructions — the underlying condition is sequenced before this code when present. See the Code First notes
  2. 3 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
  3. 11 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name N18 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: N19 — Unspecified kidney failure.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 2 Code First instructions across 2 chapters: D63.1 — Anemia in chronic kidney disease, I5A — Non-ischemic myocardial injury (non-traumatic).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

Referenced by 1 Use Additional Code instruction: I75.81 — Atheroembolism of kidney.

These codes instruct coders to additionally report this code when it applies.

Referenced by 12 Code Also instructions across 3 chapters: D59.3 — Hemolytic-uremic syndrome, E20.810 — Autosomal dominant hypocalcemia, N00 — Acute nephritic syndrome, N00-N08 — Glomerular diseases (N00-N08), N01 — Rapidly progressive nephritic syndrome, N02 — Recurrent and persistent hematuria, N03 — Chronic nephritic syndrome, N04 — Nephrotic syndrome, N05 — Unspecified nephritic syndrome, N06 — Isolated proteinuria with specified morphological lesion, N07 — Hereditary nephropathy, not elsewhere classified, N08 — Glomerular disorders in diseases classified elsewhere.

These codes suggest coding this condition alongside when both are present.

Contextual Map

Every relationship of N18 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run N18 with these 24 related codes in Claim Check

Hierarchy

Excludes2 (15)

Code First

Use Additional Code

Referenced by Excludes1 notes

Referenced by Code First instructions

Referenced by Use Additional Code instructions

  • I75.81 — Atheroembolism of kidney[Use Additional Code]: “code for any associated acute kidney failure and chronic kidney disease (N17.-, N18.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027

Referenced by Code Also instructions (12)

Nearest codes (10)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Relevant guides

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Common coding questions

MedCoder editorial

Can N18 be billed directly?

No. N18 (Chronic kidney disease (CKD)) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2027), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder-derived relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder editorial explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "N18 — Chronic kidney disease (CKD)." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/n18-chronic-kidney-disease-ckd

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Chronic kidney disease (CKD)

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to N18 in its code family, with their registry titles.